Hong Kong Earth Hour

This combo shows (L to R) the Bank of China building, the Cheung Kong Centre, the HSBC Building and the Standard Chartered Bank building and the colonial Legislative Council building (bottom L) just before Earth Hour (pictured top) and then during (pictured bottom) as Hong Kong turns out its lights on March 28, 2009. (Photo by Mike Clarke/AFP/Getty Images)

This combo shows (L to R) the Bank of China building, the Cheung Kong Centre, the HSBC Building and the Standard Chartered Bank building and the colonial Legislative Council building (bottom L) just before Earth Hour (pictured top) and then during (pictured bottom) as Hong Kong turns out its lights on March 28, 2009. (Photo by Mike Clarke/AFP/Getty Images)

This combo shows (L to R) the Bank of China building, the Cheung Kong Centre, the HSBC Building and the Standard Chartered Bank building and the colonial Legislative Council building (bottom L) just before Earth Hour (pictured top) and then during (pictured bottom) as Hong Kong turns out its lights on March 28, 2009. (Photo by Mike Clarke/AFP/Getty Images)